The molecular core facility provides services to investigators that involve either short- or long-term use of molecular techniques. It is our experience that two types of investigators are interested in our services. The first type of investigator is one who is not currently equipped to conduct experiments involving molecular biology, but recognize the advantages that can be derived by studying their experimental system on a molecular level. Investigators in this group may not be able or interested in making the investment in the equipment and supplies that are required to utilize molecular techniques. For example, this investigator may need to evaluate gene expression in their experimental system. The second type of investigator is one who is already active in molecular biology, but appreciates the advantage in both time and research funds to take advantage of our services. This type of investigator may recognize that it is possible to utilize the Molecular Core and continue to carry out other molecular studies without the need to stop to prepare molecular constructs, or measure gene expression, with precious limited resources of their own. An example would be an investigator who would like to stably express an epitope-tagged form of one of the opioid receptors in a convenient cell line. An additional example would be an investigator who is interested in measuring gene expression in vivo following drug treatment, and would like to have information about the activity of a gene which is likely to be involved in a regulatory signal transduction pathway. We provide services for investigators who span a variety of disciplines, and we carry out our work either in direct collaboration with the investigator (and their colleagues), or we carry out our work independently and pass along the product of our work to the investigator (e.g., in the form of a molecular construct, or in the form of a stably-transfected cell line).